Medical Student Research Fellowship for Summer 2008
Mentor: Lisa Halvorson, MD
Department: OB/GYN- Division of Reproductive Endocrinology and Infertility
Room number: F2.302
Mail Code: 9032
Phone number: 214-648-2309
E-mail: Lisa.Halvorson@UTSouthwestern.edu
Project title: Gonadotropin gene regulation
Human subjects IRB approved project number (where applicable): not applicable
Animal subjects IRB approved project number (where applicable): 0980-07-03-01
Project Type: basic research
Brief Description of Project:
Normal female reproductive function requires precise quantitative and temporal
regulation of the hypothalamic-pituitary-ovarian axis. The overall objective
of our laboratory is to understand neuroendocrine control of reproduction, with
a focus on the pituitary gonadotrope cells which produce the gonadotropins,
luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
A long-standing project focuses on the transcription factors and associated
DNA-regulatory elements which mediate basal and GnRH-induced expression of the
luteinizing hormone -subunit gene. The orphan nuclear hormone receptor, steroidogenic
factor-1, is known to be critical for expression of the LH subunit. We now have
evidence that a closely related transcription factor, liver receptor homologue-1,
is also involved in regulation of the LH gene. We are now in the process of
comparing and contrasting the roles of these two factors on expression of this
gene as well as the GnRH-receptor gene.
Recent data has suggested that gonadotropes secrete a peptide hormone known
as PACAP (pituitary adenylate-cyclase activating peptide). As suggested by its
name, PACAP stimulates the cAMP/protein kinase A system, thereby increasing
expression of pituitary genes, including luteinizing hormone and follicle-stimulating
hormone. Thus, PACAP may act as an autocrine factor in gonadotropes (ie., PACAP
is produced by and acts on gonadotrope cells). We have begun to identify and
characterize factors which regulate expression of the PACAP gene, focusing on
hormones with known importance to reproduction such a gonadotropin-releasing
hormone (GnRH), steroids, and PACAP itself.
Each student will choose a focused part of a project which will allow them to
master a reasonable number of techniques and obtain a clear result. Techniques
used in the laboratory include animal models (not required) and classical molecular
biology approaches (eg., cell culture, transient transfection of DNA constructs,
gel shift analysis, Western analysis, siRNA, ChIP, and DNA mutagenesis).
Previous Research Activities or Publications with Medical Students:
Litsa Lambrakos - Abstract: Society for Gynecologic Investigation, 2006. Awarded
MD with Distinction in Research (Spring, 2007)
Ignacio Montoya - Abstracts: Annual Medical Student Research Forum, 2003; Society
for Gynecologic Investigation, 2004; Society for Gynecologic Investigation,
2005